1230844 玖、發明說明： 【發明所屬之技術領域】 本&明係關於一種微影投影裝置，其包括： -一輻射系統，其用以提供一輻射投影光束； -一支樓結構，其用以支撐圖案化構件，該等圖案化構件 則用來根據—所需圖案將該投影光束圖案化； -一基板台，其用於固定一基板； • 一投影系統，其用於將該圖案化的光束投影在基板的目 標部分上； -一底座； -一平衡塊；以及 - 定位致動器，連接於該基板台或該支撐結構與該平衡 塊之間’用於在平衡塊與該基板台或該支撐結構之間產生 一反作用力，從而相對於該投影系統來定位該基板台或該 支撐結構。 【先前技術】 此處所用術語「圖案化構件」應廣義解釋為可用以賦予 進入之輻射光束一圖案化之斷面的構件，該圖案化之斷面 係對應於需建立於基板目標部分的一圖案；本文中亦可使 用術語「光閥」。一般而言，該圖案係與建立於目標部分 的元件的一特別功能層有關，如一積體電路或其他元件（見 下文）。此類圖案化構件的實例包括： -一遮罩。遮罩的概念在微影術中廣為人知，它並包括如 二進制、交替式相移及衰減式相移等遮罩類型，以及各 85842 1230844 種混合的遮罩類型。此種遮罩放在輕射光束中，將導致 照射在遮罩上的輕射依據遮罩上圖案作選擇性透射（於透 射遮罩的狀況）或反射（於反射遮罩的狀況）。在遮罩的狀 況中’該支撐結構-般是—遮罩台，其確保遮罩可被支 撐於進人的ϋ射光束中—所f位置，並於需要時可相對 於光束移動。 -可程式化鏡面陣列。此種元件的一實例為—矩陣可定 址表面’具有一黏彈性控制層及—反射表面。此種裝置 的基本原理為(例如)反射表面的已定址區域反射入射光為 繞射光未定址區域則反射人射光為非繞射光。利用 適當滤波器可自反射光束中過遽出該非繞射光，僅留下 繞射光；如此光束即依矩陣可定址表面的定址圖案成為 圖木化光束。一可程式鏡面陣列的替代性具體實施例使 用-微小鏡面的矩陣配置’藉由施加一適當的局部電場 (電磁、靜電）或使用-壓電起動構件，各個鏡面可單獨繞 :轴傾斜。再者’孩等鏡面為矩陣可^址鏡面，使得該 等定址1¾面可以不同方向反射人射的輻射光束至未定址 的銃面’以此万式’反射光束可根據矩陣可定址鏡面的 疋址圖案®案彳可使料當的電子構件，以執行所需 的矩陣疋址。在上述的兩種狀況下，圖案化構件可包括 二或多個可程式鏡面陣列。有關本文所述的鏡面陣列之 詳細貝Λ ’ 4參Μ例如美ϋ專利us 5,296,891及us 5 523⑼ 及PCT專利巾請案wo 98/38597及w〇 _〇96，其以提及方 式併入本文。就可程式鏡面陣列而言，該支撐結構可以 85842 1230844 例如框架或臺面方式具體化，且視需要可為固定或移動 式。 -一可程式LCD陣列。此種結構的實例可於美國專利US 5,229,872中找到，其以提及方式併入本文。如上所述，此 種狀況的支撐結構可以例如框架或臺面方式具體化，並 視需要可為固定或移動式。 基於簡化的目的，本文其餘部分將在特定位置明確說明 有關遮罩及遮罩台的實例，然而，此類實例中所述的通用 原理應較廣泛地適用於上述圖案化構件。 微影投影裝置可用於例如積體電路（IC)的製造上。在此種 情況中，圖案化構件可產生對應於IC中個別層的電路圖案， 並可將此圖案映射於已塗佈一層對輻射敏感的材料（抗蝕劑） 之基板（碎曰曰圓）上的目標邵分（如包括一或多個晶粒）。一 般而έ，單一晶圓可包括相鄰目標部分所構成之整個網路， 其將依次由投影系統逐個照射。在本裝置中，利用遮罩臺 上的遮罩進行圖案化，可區分戌兩種不同類型的機器。在 一種微影投影裝置中，一動作將整個遮罩圖案曝露於目標 部分上，讓每一目標部分都輻射到，此種裝置一般稱為晶 圓步進機（wafer stepper)。在另一種一般稱為步進掃描裝置（step_ and_scan apparatus)的替代性裝置中，於投影光束下以一既定參 考方向（「掃描」方向）逐步掃描遮罩圖案以照射每一目標部 分’並與此方向平行或反平行同步掃描基板台；因通常此 投影系統具有一放大因子Μ(通常<1)，故掃描基板台的速率 V將為掃描遮罩台速率的μ倍。有關上述微影元件的更多資 85842 1230844 訊可於例如US 6,046,792中收集到，其以提及方式併入本文 中 〇 在使用微影投影裝置的製造方法中，於至少部分由一層 對輕射敏感的材料（抗蚀劑）覆蓋的基板上映射一圖案（例如 在一遮罩中）。在此成像步驟之前，基板可經各種程序處理， 例如打底(priming)、抗姓劑塗佈及軟烘（soft bake)。曝光之後， 該基板可接受其他處理，例如曝光後烘乾（post-exposure bake ; PEB)、顯影、硬烘（hard bake)及測量/檢查成像之特徵。這程 序陣列係用來作為一基礎，以圖案化一元件如1C的個別層。 接著，此種圖案化層可再經過各種方法處理，例如蝕刻、 離子植入（摻雜）、金屬化、氧化、化學機械研磨等，所有方 法皆為各層表面處理所需。如果需要數個層，則整個程序， 或其一變化步驟必須針對每個新的層重覆。最後，在基板（晶 圓）上將呈現一元件陣列。然後這些元件將藉由一技術彼此 隔開，例如切割或鋸開，然後該等個別的元件可安裝在一 載具上，連接到插針等。關於Λ種方法的進一步資訊可參 閱例如書本「微晶片製造：半導體處理的實用導引」（Microchip Fabrication ： A Practical Guide to Semiconductor Processing)，第三版， 由 Peter van Zant 所著，McGraw Hill Publishing 公司，1997 年，ISBN 0-07-067250-4，其以提及方式併入本文中。 為簡化起見，以下稱投影系統為「透鏡」；不過，此術 語必須作廣義的解釋以包括各種投影系統，例如，包含折 射光學、反射光學及反折射的系統。該福射系統亦可包含 根據任何此等設計類型操作的組件，用以引導、塑造或控 85842 1230844 制輪射的投影光束，且此種組件以下也可以統稱或獨稱為 「透鏡」。另外，此微影裝置可能是一種具有兩個或以上 基板台（及/或兩個以上遮罩台）的形式。在此種「多平A 元件中’可以平行使用額外臺面，或在一或多個臺面上進 行準備步驟，而其他一或多個臺面則用於曝光。雙平臺微 影裝置在例如US 5,969,441及WO 98/40791中均有說明，其以提 及方式併入本文中。 在一微影投影裝置中，位於一支撐結構上的一遮罩上的 資訊以一所謂的掃描方法投影至該基板臺上，其中，該支 撑結構與基板台以怪定速度同步移動。由於該基板台的加 速度通常為5至100 m/s2，且一基板台的典型重量約為1〇至 200 [Kg]，故該等加速或減速力可以很大。若此基板台係藉 由附著於一底座上的一致動器來移動，則該反作用力會轉 移至此底座上。若此反作用力係直接轉移至此底座上，則 這會導致該等底座的特徵頻率（典型係為10至50 大量激 發。此係導致底座震動，影響該缉影透鏡的震動隔離系統。 部分震動於是可傳輸至該等投影透鏡。由於該基板台係相 對於該等投影透鏡定位，故此投影透鏡震動會產生伺服位 置誤差，影響成像方法。 此種反作用力的影響可以藉由使用美國專利US 6,262,796中 說明的一自由安裝的平衡塊而得到降低。此步驟之完成係 藉由：在基板台與平衡塊之間使用一定位致動器，使得該 基板台朝一方向移動，而該平衡塊則朝相反方向移動（移動 量等於該基板台移動距離乘以該基板台同該平衡塊之質量 85842 -10- !23〇844 匕的乘積)以產生—反作用力。按此方法，不會有太多反作 用力傳至該底座，並且該平衡塊與該基板台之組合重心相 對於該底座保持實質上恆定。 右此自由纟t的平衡塊具有較大行牙呈，則該平衡塊在移 動時需要指導，且特別當該平衡塊係處於真空之中時，用 万、a平衡塊的纜線傳輸及管道輸送效用會很難排列且造成 機器龐大。 2使微影投影裝置的尺寸最小化，可以增加該平衡塊的 貝里以在3平衡塊的無摩擦支撐附近增加複雜性為代價， 使該平衡塊所需的行程減少。 以上問題對用於支撐該等圖案化構件的支撐結構同樣適 用，該支撐結構亦需要㈣該投影系統移冑，並且可以使 用平衡塊來移動。 【發明内容】 本毛月的目“疋為該自由安裝的平衡塊提供一替代方 案，其至少可以部分消除上述問題之一。 根據本發明，此目標及其它目標在本文開始段^中說明 的-微影裝置中得以實現’該裝置的特徵在於：該平衡塊 係藉由一彈性耦合結構與該底座耦合，使得該平衡塊具有〇3 與10赫茲之間的一懸掛特徵頻率，以便將該反作用力之一 部分施加至該底座上。 按此方法，僅有部分反作用力藉由該彈性耦合結構傳輸 至該底座。因為隨後僅有低頻率震動按如下過程傳輸至該 底座，故最好採用該平衡塊的〇·3與關兹之間的—特徵頻 85842 -11 - 1230844 率：藉由基板台或支撐結構以高於約1〇至15赫茲的頻率移 動而產生的反作用力幾乎未傳輸至底座，因為在此等頻率 時，該平衡塊未受到該彈性耦合結構的影響，且其作用僅 相當於用於此等頻率的一自由平衡塊。對該基板台或支撐 〜構不利的干擾通#為頻率向於1 〇赫兹的干擾，但該平衡 塊在此頻率區域並不傳遞較大的干擾。然而，藉由該基板 台或支撐結構的長行程操作所產生的加速力（其典型具有頻 率低於10赫茲的一能量）係傳輸到該底座。位於該平衡塊上 的孩反作用力的一部分為彈性耦合結構的彈簧勁度所吸 收，且此係僅需要一小行程。已經發現，傳輸至底座的此 類較低頻率力在對該裝置產生有害影響前其大小可以相當 高。按此方法’在依據本發明的一典型微影投影裝置中， m平衡塊的行程典型係低於約20 _。舉例而言，該彈性耦 合結構可以包括板片彈簧、扭轉彈簧或其他機械彈簧、具 有似彈貪特徵的磁體裝配件等。而且，應該注意，該彈性 搞合結構具有使該平衡塊朝其中性位置移動的趨勢。此會 在（例如）該定位致動器的初始化期間產生好處。 在依據本發明的一項具體實施例中，該平衡塊係得到該 底座上一軸承的進一步支撐。此軸承可以是（例如）位於該底 座與該平衡塊之間的一空氣軸承。此係提供一支撐，使得 該平衡塊可沿平移方向完成所需行程。 在依據本發明的一項具體實施例中，該裝置之結構與排 列應使得，在該基板台或該支撐結構的定位期間移動時， 該基板台或該支撐結構與該平衡塊的組合重心之位置亦會 85842 -12- 1230844 相對於底座移動。由於該平衡塊係彈性耦合至該底座，故 在巧基板台或該支撐結構的定位期間移動時，其重心不會 維持原位置。 _本毛月的项具體實施例中，該裝置進一步包括一平 f塊致動器’用於控制該平衡塊的位置。在此項主動具體 爲她例中’藏平衡塊致動器可以與該彈性耦合結構平行定 丄〃 Τ M平衡塊亦藉由該平衡塊致動器與該底座耦合。 此平衡塊致動器可用於以一較低頻率向該平衡塊施加位置 。lL* — > v . 我·此万法，在此平移方向上的較大但頻率較低的 力可以以較低頻率施加至該底座。該平衡塊致動器也可以 使Θ平衡塊系統的共振頻率（由該平衡塊的質量與該彈性耦 y μ構對底座的勁度所形成）衰減，並使該底座與該平衡塊 之間的力I轉移在10赫茲以上的頻率範圍内進一步減少。 在本發明的一項具體實施例中，該平衡塊致動器係應用 過滤的前饋程式，以使該等力平滑地傳至該底座。該平 衡鬼致動态可以係(例如)一氣動、液壓、電磁或壓電致動器。 在本么明的另一項具體實施例中，該裝置包括與該彈性 结構平行定位的—彈簧減震器系統，纟中，該平衡塊 亦藉由4彈3減震器系統與該底座耦合。該彈簧減震器系 統:使不同類型的彈簧（機械、空氣、磁性）與（例如）黏性減 震器、渦流減震器等不同類型的減震器組合起來。為獲得 斤為的轉移特性，將彈簧與減震器並聯及串聯均可。該被 動=體貫施例的—好處在於，其提供_種費用較少的解決 万案’且-般係比以犧牲某性能為代價的主動解決方案更 85842 -13 - 1230844 堅固耐用。 4彈更減震器系統最好包括至少一具有彈簧特性的元 件，其與至少一具有減震器特性的元件辛聯。在該彈性耦 占、、’口構貝貝上具有一彈簧特性的一項具體實施例中，此系 統係進一步稱為KDK系統。該減震器可以作為一黏性減震 咨或任何其他類型的減震器來實施。 S減震咨最好係作為一渦流減震器來實施，因為此可在 耐久性、可靠性、可維護性及污染方面提供好處。此 系統使該平衡塊系統的共振頻率（由該平衡塊的質量與該彈 f耦5〜構對底座的勁度所形成）衰減，並使該底座與該平 衡塊之間的力量轉移在10赫茲以上的頻率範圍内進一步減 y这彈簧減震器系統亦可藉由應用兼具彈簧及減震器之 特性的組件（如類似橡膠的材料或記憶合金）來實現。 在本發明的一項具體實施例中，該平衡塊係採用減震係 數b為〇·3與〇.9(最好是〇65至〇75)之間的一減震器來減震。按 此方法，施加到底座上的該基板台的長行程反作用力無法 放大。 在本發明的一項具體實施例中，該減震器係與該彈性耦 口結構平行定位，其中，該平衡塊亦藉由該減震器與該底 座耦合。該減震可以藉由一單獨組件來實現，或亦可藉由 具有内邵減震器的該彈性耦合結構本身來獲得。 在本發明的一項具體實施例中，該平衡塊減震時的減震 係數為b，其係作為頻率的一函數而變化。舉例而言，可以 採用渦泥減震器。而且，若一平衡塊致動器係用於該平 85842 -14- 1230844 衡塊的王動性減震1 f力’則肖減震係數可以作為頻率的一 函數而變化。 在本發明的一項具體實施例中，該裝置進一步包括一控 制器，用於週期性施加一位置控制迴路。舉例而言，此可 施加用來防止該平衡塊因該基板台或支撐結構的反復移動 而和位，或用來彌補該平衡塊的摩擦，或用來修正該彈性 耦合結構的滯後效應。 在本發明的一項具體實施例中，具有低於3至1〇赫茲一頻 率的該反作用力的5〇%至1〇〇%係藉由該彈性耦合結構施加至 違底座上。 在本發明的一項具體實施例中，該裝置進一步包括一真 玄室’用於容納該基板台或支撐結構與該平衡塊。由於其 行程小，故本發明之平衡塊特別適合於此類應用。 在本發明的一項具體實施例中，於該平衡塊與該真空室 之一壁之間應用一風箱。由於該平衡塊行程小，故此係有 可能，且有好處，因為任何向該平衡塊提供效用的纜線及 管道（例如）用於空氣軸承的空氣、或用於位置感應器的電 纜，均可穿過該風箱來佈線，並因此無須為真空依賴型。 在本發明的一項具體實施例中，該風箱至少形成該彈性 ♦禹合結構的一部分。視勁度而定’遠風柏可以部分或全部 取代該平衡塊與該底座之間之彈性耦合結構的功能。 在本發明的一項具體實施例中，該平衡塊致動器或該彈 簧減震器系統係藉由該風箱與該平衡塊連接。根據本發明 的另一方面，提供一種元件製造方法，其步驟包括： 85842 -15 - 1230844 才疋供基板，其至少有一部分為位於一底座上之一基板 台上的輻射敏感材料層所覆蓋； 利用輻射系統提供一輻射投影光束； _利用為一支撐結構所支撐的圖案化構件賦予投影光束一 圖案式之斷面； I將圖案化之輻射光束投影至輻射敏感材料層之一目標部 _藉由在該基板台或該支撐結構與一平衡塊之間產生一反 作用力，從而相對於該底座來移動該基板台或該支撐結構， 其特徵在於係藉由一彈性耦合結構將該反作用力之一部分 傳輸至該底座，該彈性耦合結構係以〇·3至1〇赫茲之間的一 懸掛特徵頻率將該平衡塊耦合至該底座。 雖然本文提供使用本發明的裝置製造IC的特定參考，但 必屑明白该裝置具有許多其他的應用。舉例而言，可用於 製造整合光學系統、磁疇記憶體之導引及偵測圖案、液晶 顯示器面板、薄膜磁頭等。專業人士將可瞭解到在此類替 代應用中’在此文中任何所使用的術語「主光罩」、「晶 圓」或「晶粒」必須分別考慮由更為一般性的術語「遮罩」、 「基板」及「目標部分」所取代。 在本文件中所使用的術語「輻射」及「光束」可用來包 含所有型式的電磁輻射，包括紫外線輻射（如波長為365、 248、193、157或126 nm者）和EUV(遠紫外線輻射，如具有波 長範圍5至20 nm者）’以及諸如離子束或電子束之類的粒子 束。 85842 -16 - 1230844 【實施方式】 圖1為一微影投影裝置之相關零件的示意圖。該裝 栝： 匕 射系、·’先Ex、il ,用於提供一輻射投影光束pB(如z線、 UV EUV^射、電子束等），在此特定情況中，其亦包括_ 輻射源LA ; 一弟一物件台（遮罩台）MT，具有用以支撐遮罩MA(例如 主光罩）的遮罩支架，並與第一定位構件？1^連接以相 於項目PL精確定位該遮罩； 一第二物件台（基板台）WT，具有用〃支擇基板w(例如— 塗佈了抗蝕劑的矽晶圓)的-基板支架，並與第二基板台定 位構件PW連接’以相對於項目此精確定位基板； -投影系統（「透鏡」）pL(例如一鏡面系統），用以將遮罩 MA的又照射部分映射於基板w的目標部分〔（例如包含一 或多個晶粒）上。 如此處所描述，該裝置屬一反舞型（即具有一反射遮罩）。 然而，一般而言，它亦可屬一透射型（例如具有一透射遮罩）。 或者，該裝置可採用另一種圖案化構件，例如—上述類型 的可程式化鏡面陣列。 / 輻射源LA(例如一雷射產生放電電漿源）產生一輻射光 束。此光束直接地或在穿過調節構件如—光束擴張二之 後’射入一照射系統（照射器）IL中。照射器几可包含調整構 件AM’用來設定光束中強度分佈的外徑向範圍及/或内徑 向範圍(-般分別稱•外及①内）。此外，其一般包含許多 85842 -17- 1230844 其他組件，例如一整合器IN及一聚光器CO。依此方式，照 射在該遮罩MA上的光束PB具有所想要的均勻性及在其斷面 中的強度分佈。 圖1中應注意的是：輻射源LA可位於微影投影裝置的外殼 中（通常當輻射源LA是一（例如）水銀燈時，即是如此），但它 亦可與微影投影裝置距離遙遠，其所產生之輻射光束被導 入裝置中（例如藉助適當導引鏡面）；當輻射源LA為一準分 子雷射（excimer laser)時，通常是後面這種狀況。本發明及申 請專利範圍包含這兩種情況。 該光束PB後續截斷該遮罩MA，其係夾持在 上。在行經該遮罩μα之後，該光束PB穿過該透鏡PL，其將 孩光束PB聚焦在該基板w的一目標部分c上。藉助該第二定 位構件（及干涉量測構件IF),該基板台界1可準確地移動， 例如藉以在該光束PB的路徑中定位不同的目標部分C。同樣 ’可用第一定位構件以相關於光束PB的路徑精確定位遮 罩Μ A例如，自遮罩庫機械性g取出遮罩μ A之後，或在掃 描奇中。一般說來，該等物件台MT、WT的移動會在一長行 私模組（粗略定位）及一短行程模組（精確定位）的輔助下實 現，咸等二模組並未在圖丨中詳細說明。應該注意，一般說 來咸長行私模組使得該基板台的長行程移動實質上在一 =面内進行，而該遮罩台的長行程模組使得長行程移動實 、人 著個方向。然而，若在晶圓步進機的狀況中（相對 万；步進掃描裝置），遮罩台⑽可能僅連接至一短行程致動器 以啟動六度自由度的短行程移動，或為固定。 85842 -18 - 1230844 上述裝置可用於兩種不同模式中： 1·在步進模式中，該遮罩SMT基本上保持靜止，而一整 個遮罩影像在一次處理中（即一單一「快閃」）中投射到一目 核邵分c上。然後該基板台偏移到义及/或y方向上，所 以不同的目標邵分C可由該光束pb照射； 2·在掃描模式中，實質上適用相同的狀況，但特定目標部 分c並非於單一「快閃」中曝光。而是，遮罩台Μτ在一特 足方向（所謂的「掃描方向」，例如y方向）以一速度v移動， 使投影光束PB掃描一遮罩影像；同時基板台WT則與之·同向 或反向以速度V=Mv移動，其中μ為透鏡PL的放大因子（典型 地’ Μ-1/4或1/5)。如此’可曝光一相對較大的目標部分c而 不需犧牲解析度。 本發明將參考基板台WT來詳細說明。然而，本發明同樣 適用於遮罩台ΜΤ。 從圖1中可以看到，一典型的微影裝置包括其上支撐有各 種組件的一底座BF。 舉例而言，圖2中說明各組件在該底座上安裝的示意圖。 此圖顯示了最好係與地面1〇牢固連接的該底座BF。該投影 系統PL由於安裝到了一度量架50之上而未受到底座BF之震 動的影響，該度量架50順勢以一主動防震系統（active vibmtiQn isolation system ; AVIS)的一軟懸掛系統55連接於該底座BF上。 該晶圓臺係藉由一致動器（2〇)來驅動，且該反作用力係施加 於該平衡塊（BM)上。一彈性耦合結構150係在該平衡塊與該 底座之間連接。該彈性耦合結構150的勁度之選擇應使得該 85842 -19- 1230844 平衡塊以位於該平移（水平）平面为 、、 J卞面内的一懸掛特徵頻率來安裝 於該底座BF上，該懸掛特徵頻阜 Λ、手 <靶圍為0.3至10赫茲，最 好係為1至6赫兹。一適當的縣掛姑 心掛特欲頻率約為3赫茲。 該懸掛特徵頻率fG可依據等式⑴來計算·· /〇: :一 \JEnas ① 其中，kspring為彈性轉合結構15〇的彈簧的勁度，且、為平衡 塊BM的質量。若將該平衡塊的懸掛特徵頻率設置在。則 赫兹範圍Θ，則可以核在該平移水平平面中之二方向上 允許自該平衡塊倒人該底座的較大低頻力（在低於3赫兹的 -頻率時，力達到約5_牛頓）。在此實例巾，與彈性輕合 結構150平行安放了-減震器17〇及—平衡塊致動器觸。視 需要可將彈_合結構15G mi職該平衡塊致動器裝 風箱120。按此方法，該彈性韓合結構、該減震器及該 平衡塊致動器係從定位該基板台術及該平衡塊的舱室中脫 離出來。使用風箱可在有關污染或除氣特性等方面，對彈 性耦合結構、減震器及平衡塊致動器強加較少的苛刻條件。 平衡塊致動器卿係用於修正平衡塊的位置，因為該平衡塊 有從正確位置移位的趨勢。此移位可視為遲滯，其係由於（例 如）底座BF與平衡塊3河之間的摩擦造成❶該修正係作為一 封閉迴路控制而藉由一控制器來施加，該控制器控制平衡 塊致動器100，並週期性地（例如每毫秒）施加一力（如有必 要），使平衡塊BM實質上居中，以防止因基板台的反復移動 所造成的平衡塊移位。 85842 -20- 1230844 致動器100也可用於抑制平衡塊BM的移動，以避免平衡塊 BM的纏繞，即共振。或者，此功能可以藉由單獨的機械被 動減震器170來實施。無論所用的減震形式為何，有關的減 震係數b較佳應位於〇·5與ι·〇之間’最好係位於〇必與〇乃之 間。若使用平衡塊致動器100，則其係可以作為一主動減震 器來使用，該減震係數b係作為頻率的一函數而變化。例如， b=0.7的一減震係數可以用來達到一臨界頻率（例如，位於〇.3 至20赫茲區域内），隨後該減震係數減小，使得在一無窮大 之頻率處，該減震係數為零。按此方法，在高頻率下從平 衡塊轉移至底座的力係少於減震係數恆定之情況。由於基 板台WT的移動頻率接近平衡塊bm的懸掛特徵頻率，故此減 震也減少了從平衡塊至底座的力轉移的振幅。 平衡塊致動器100也可用於藉由一過濾的前饋程式使以低 頻率傳輸至底座的力的斷面變平滑。此係可以藉由使底座邸 上平衡塊BM的預期反作用力通過一低通濾波器，並經平衡 塊致動器100向平衡塊BM施加一力而完成，目的是使反作用 力中的急劇變化變得平滑。在任何情況下，高頻率干擾均 不會傳至底座。 圖3顯示在真空應用中，藉由底座BF支撐的各種組件的一 替代排列。在此實例中，基板台WT係藉由連接構件12定位 於一基板台支撐架SF(其係與底座即牢固連接）上。該晶圓 臺係藉由一致動器（20)來驅動，且該反作用力係施加於該平 衡塊_)上。與-平衡塊致動器⑽平行的_彈性耦合結構 150及一減震器170係連接於平衡塊與基板台支撐架之間。在 85842 -21 - 1230844 此員具也只她例中，投影系統PL、平衡塊BM及基板台WT係 為-真2室VC所封裝，該真空室係牢固連接於底座腦上。 基板口 WT與平衡塊BM的安裝應使得與基板台支撐架SF的 表面平行的水平平面中的平移移動實質上無摩擦。此目標 可以藉由以下步驟來達到：（例如）將基板台WT從該平衡塊 處懸置，並為該平衡塊提供线軸承，或兼為該基板台及1230844 发明 Description of the invention: [Technical field to which the invention belongs] This & Ming system relates to a lithographic projection device, which includes:-a radiation system for providing a radiation projection beam;-a building structure for To support the patterned members, which are used to pattern the projected beam according to the desired pattern;-a substrate stage for fixing a substrate; • a projection system for patterning the pattern The light beam is projected on the target portion of the substrate;-a base;-a balance weight; and-a positioning actuator connected between the substrate table or the support structure and the balance weight 'for the balance weight and the substrate A reaction force is generated between the stage or the supporting structure to position the substrate stage or the supporting structure relative to the projection system. [Prior art] The term "patterned member" as used herein should be broadly interpreted as a member that can be used to impart a patterned cross-section to the incoming radiation beam, which patterned cross-section corresponds to a Pattern; the term "light valve" is also used in this article. In general, the pattern is related to a special functional layer of the component built on the target part, such as an integrated circuit or other component (see below). Examples of such patterned components include:-A mask. The concept of masks is widely known in lithography, and it includes mask types such as binary, alternating phase shift and attenuated phase shift, as well as 85842 1230844 mixed mask types. Such a mask is placed in a light beam, which will cause the light shot on the mask to be selectively transmitted (in the case of a transmission mask) or reflected (in the state of a reflection mask) according to the pattern on the mask. In the case of a mask ', the support structure-generally-a mask table, which ensures that the mask can be supported in a projected human beam-at the f position, and can be moved relative to the beam when needed. -Programmable mirror array. An example of such a component is-the matrix addressable surface 'has a viscoelastic control layer and-a reflective surface. The basic principle of such a device is, for example, that an addressed area of a reflective surface reflects incident light as a diffracted light and an unaddressed area reflects human light as non-diffracted light. By using an appropriate filter, the non-diffracted light can be extracted from the reflected beam, leaving only the diffracted light; in this way, the addressing pattern of the addressable surface of the matrix becomes a map beam. An alternative embodiment of a programmable mirror array uses a matrix configuration of tiny mirrors' by applying an appropriate local electric field (electromagnetic, electrostatic) or using a piezoelectric starter member, each mirror can be tilted individually around the axis. Furthermore, the 'mirror mirrors' are matrix-addressable mirrors, so that these addressed 1¾ planes can reflect human radiation beams to the unaddressed planes in different directions. In this way, the reflected beams can be addressed based on the matrix. Address Pattern® allows you to design electronic components to perform the required matrix addressing. In both cases, the patterned member may include two or more programmable mirror arrays. For details on the mirror arrays described herein, such as US patents US 5,296,891 and US 5 523, and PCT patents, WO 98/38597 and WO 〇 96, which are incorporated herein by reference . In the case of programmable mirror arrays, the support structure can be embodied in 85842 1230844, such as a frame or a countertop, and can be fixed or mobile as needed. -A programmable LCD array. An example of such a structure can be found in US Patent No. 5,229,872, which is incorporated herein by reference. As mentioned above, the support structure in such a situation can be embodied in a frame or countertop manner, for example, and can be fixed or mobile as needed. For the purpose of simplification, the rest of this article will clearly explain examples of masks and mask tables at specific locations; however, the general principles described in such examples should be applied more broadly to the patterned components described above. The lithographic projection device can be used, for example, in the manufacture of integrated circuits (ICs). In this case, the patterned member can generate a circuit pattern corresponding to individual layers in the IC, and can map this pattern to a substrate (broken circle) that has been coated with a layer of radiation-sensitive material (resist). On the target (such as including one or more grains). In general, a single wafer can include the entire network of adjacent target parts, which will be illuminated by the projection system one by one in turn. In this device, patterning is performed using a mask on a mask table to distinguish between two different types of machines. In a lithographic projection device, an action exposes the entire mask pattern to a target portion so that each target portion is radiated. Such a device is generally called a wafer stepper. In another alternative device commonly referred to as a step_and_scan apparatus, a mask pattern is scanned step by step under a projected light beam in a predetermined reference direction ("scanning" direction) to illuminate each target portion 'and This direction scans the substrate table in parallel or anti-parallel synchronously; because the projection system usually has a magnification factor M (usually < 1), the speed V of the scanning substrate table will be μ times the speed of the scanning mask table. More information on the above-mentioned lithographic element 85842 1230844 may be collected in, for example, US 6,046,792, which is incorporated herein by reference. In a manufacturing method using a lithographic projection device, at least part of the layer is light-emitting to the light. A pattern (eg, in a mask) is mapped on a substrate covered by a sensitive material (resist). Prior to this imaging step, the substrate may be processed by various procedures, such as priming, anti-agent coating, and soft bake. After the exposure, the substrate may undergo other processes such as post-exposure bake (PEB), development, hard bake, and measurement / inspection of imaging features. This process array is used as a basis to pattern individual layers of a component such as 1C. This patterned layer can then be processed by various methods, such as etching, ion implantation (doping), metallization, oxidation, chemical mechanical polishing, etc. All methods are required for the surface treatment of each layer. If several layers are required, the entire procedure, or one of its changing steps, must be repeated for each new layer. Finally, an array of elements will be presented on the substrate (crystal wafer). These components will then be separated from each other by a technique such as cutting or sawing, and then the individual components can be mounted on a carrier, connected to pins, and so on. Further information on Λ methods can be found in, for example, the book "Microchip Fabrication: A Practical Guide to Semiconductor Processing", Third Edition, by Peter van Zant, McGraw Hill Publishing Corporation, 1997, ISBN 0-07-067250-4, which is incorporated herein by reference. For simplicity, the projection system is hereinafter referred to as a "lens"; however, the term must be interpreted broadly to include various projection systems, for example, systems that include refractive optics, reflective optics, and refracting. The radiating system may also include components operating in accordance with any of these design types to guide, shape, or control the projection beam of 85842 1230844 wheels, and such components may also be collectively referred to as "lenses" hereinafter. In addition, the lithographic apparatus may be in the form of having two or more substrate stages (and / or two or more mask stages). In such a “multi-flat A element,” additional stages can be used in parallel, or one or more stages can be used for preparation steps, while the other stage or stages are used for exposure. Dual-stage lithography devices are described in US 5,969,441 and There is a description in WO 98/40791, which is incorporated herein by reference. In a lithographic projection device, information on a mask on a support structure is projected onto the substrate stage by a so-called scanning method. The support structure and the substrate table move synchronously at a strange speed. Since the acceleration of the substrate table is usually 5 to 100 m / s2, and the typical weight of a substrate table is about 10 to 200 [Kg], These acceleration or deceleration forces can be large. If the substrate table is moved by an actuator attached to a base, the reaction force is transferred to the base. If the reaction force is directly transferred to the base, Then this will cause the characteristic frequency of these bases (typically a large number of 10 to 50 excitation. This will cause the base to vibrate, affecting the vibration isolation system of the shadow lens. Part of the vibration can then be transmitted to the projection lenses. Because the substrate table is positioned relative to the projection lenses, the projection lens vibration will generate servo position errors and affect the imaging method. The effect of this reaction force can be achieved by using a freely mounted balance block described in US Patent No. 6,262,796. It is reduced. This step is completed by using a positioning actuator between the substrate table and the balance block, so that the substrate table moves in one direction, and the balance block moves in the opposite direction (the movement amount is equal to the substrate The moving distance of the stage is multiplied by the product of the base plate stage and the weight of the balance block (85842 -10-! 23〇844) to produce a reaction force. According to this method, not much reaction force is transmitted to the base, and the The combined center of gravity of the balance weight and the base plate platform remains substantially constant relative to the base. To the right of this free weight, the balance weight has a large line, so the balance weight needs guidance when moving, and especially when the balance weight system is When in a vacuum, the cable transmission and pipeline transportation effects of the 10,000-a balance block will be difficult to arrange and cause the machine to be bulky. 2 Make the scale of the lithographic projection device Minimizing the size can increase the balance's Bailey. At the cost of increasing the complexity near the frictionless support of the 3 balance weight, the stroke required by the balance weight is reduced. The supporting structure is also applicable. The supporting structure also needs to be moved by the projection system and can be moved by using the balance weight. [Summary of the Invention] The objective of this month is to provide an alternative solution for the freely installed balance weight, which at least One of the above problems can be partially eliminated. According to the present invention, this objective and other objectives are achieved in the lithography device described in the opening paragraph of this article. The base is coupled such that the counterweight has a characteristic frequency of suspension between 0 3 and 10 Hz in order to apply a portion of the reaction force to the base. According to this method, only a part of the reaction force is transmitted to the base through the elastic coupling structure. Since only low-frequency vibrations are transmitted to the base in the following process, it is best to use the characteristic frequency between 0.3 and Guanz of the balance weight—85842 -11-1230844. The reaction force due to frequency shifts above about 10 to 15 Hz is hardly transmitted to the base, because at these frequencies, the balance weight is not affected by the elastic coupling structure, and its effect is only equivalent to that used for this A free balance block of equal frequency. The unfavorable interference channel on the base plate or support is interference at a frequency of 10 Hz, but the balance block does not transmit large interference in this frequency region. However, the acceleration force (which typically has an energy frequency lower than 10 Hz) generated by the long stroke operation of the substrate stage or support structure is transmitted to the base. A part of the reaction force on the balance weight is absorbed by the spring stiffness of the elastic coupling structure, and the system requires only a small stroke. It has been found that such lower frequency forces transmitted to the base can be quite high in magnitude before they can adversely affect the device. According to this method ', in a typical lithographic projection apparatus according to the present invention, the stroke of the m balance weight is typically less than about 20 mm. For example, the elastic coupling structure may include a leaf spring, a torsion spring or other mechanical spring, a magnet assembly having a spring-like characteristic, and the like. Moreover, it should be noted that the elastic engaging structure has a tendency to move the balance weight toward its neutral position. This can result in, for example, the initialization of the positioning actuator. In a specific embodiment according to the present invention, the balance weight is further supported by a bearing on the base. The bearing may be, for example, an air bearing located between the base and the weight. This system provides a support so that the counterweight can complete the required stroke in the translation direction. In a specific embodiment according to the present invention, the structure and arrangement of the device should be such that when the substrate stage or the supporting structure moves during positioning, the combined center of gravity of the substrate stage or the supporting structure and the balance weight The position will also move 85842 -12- 1230844 relative to the base. Since the balance weight is elastically coupled to the base, its center of gravity will not maintain its original position when it is moved during the positioning of the smart substrate stage or the support structure. _ In the specific embodiment of this Maoyue, the device further includes a flat f-block actuator 'for controlling the position of the balance block. In this example, the ‘hidden’ balance weight actuator can be determined in parallel with the elastic coupling structure. The T M balance weight is also coupled to the base through the balance weight actuator. This balance weight actuator can be used to apply a position to the balance weight at a lower frequency. lL * — &v; I. In this method, a larger but lower frequency force in this translation direction can be applied to the base at a lower frequency. The balance weight actuator can also attenuate the resonance frequency of the Θ balance weight system (formed by the mass of the balance weight and the stiffness of the elastic coupling y μ structure to the base), and make the space between the base and the balance weight The force I transfer is further reduced in the frequency range above 10 Hz. In a specific embodiment of the present invention, the balance weight actuator is a feedforward program using filtering, so that the forces are smoothly transmitted to the base. The balancing actuation can be, for example, a pneumatic, hydraulic, electromagnetic or piezoelectric actuator. In another specific embodiment of this Meming, the device includes a spring shock absorber system positioned parallel to the elastic structure. In the middle, the balance weight is also coupled to the base by a 4 spring 3 shock absorber system. . The spring shock absorber system: different types of springs (mechanical, air, magnetic) are combined with, for example, viscous shock absorbers, eddy current shock absorbers, and other types of shock absorbers. In order to obtain the transfer characteristic of the load, the spring and the shock absorber can be connected in parallel or in series. This passive is a practical example—the advantage is that it provides less costly solutions ”and is generally more robust than an active solution at the expense of some performance 85842 -13-1230844. The four-stroke shock absorber system preferably includes at least one element having spring characteristics, which is connected to at least one element having shock characteristics. In a specific embodiment in which the elastic coupling, '' portion structure has a spring characteristic, this system is further referred to as a KDK system. The shock absorber can be implemented as a viscous shock absorber or any other type of shock absorber. The S shock absorber is best implemented as an eddy current shock absorber because it provides benefits in terms of durability, reliability, maintainability and pollution. This system attenuates the resonance frequency of the balance block system (formed by the mass of the balance block and the stiffness of the base 5 to the stiffness of the base), and transfers the force between the base and the balance block at 10 In the frequency range above Hertz, the spring shock absorber system can be further reduced by applying components that have characteristics of both springs and shock absorbers (such as rubber-like materials or memory alloys). In a specific embodiment of the present invention, the balance block uses a shock absorber with a shock absorption coefficient b between 0.3 and 0.9 (preferably 065 to 075) to reduce the vibration. In this way, the long-stroke reaction force of the substrate stage applied to the base cannot be amplified. In a specific embodiment of the present invention, the shock absorber is positioned in parallel with the elastic coupling structure, and the balance weight is also coupled to the base through the shock absorber. The damping can be achieved by a separate component, or it can also be obtained by the elastic coupling structure itself with an internal shock absorber. In a specific embodiment of the present invention, the damping coefficient of the balance weight when damping is b, which changes as a function of frequency. For example, a vortex mud damper can be used. Moreover, if a balance weight actuator is used for the flat 85842 -14-1230844 weight dynamic damping of 1f force ', the Xiao damping coefficient can be changed as a function of frequency. In a specific embodiment of the invention, the device further comprises a controller for periodically applying a position control loop. For example, this may be applied to prevent the balance weight from being reset due to repeated movement of the base plate or support structure, or to compensate for the friction of the balance weight, or to modify the hysteresis effect of the elastic coupling structure. In a specific embodiment of the present invention, 50% to 100% of the reaction force having a frequency lower than 3 to 10 Hz is applied to the violation base by the elastic coupling structure. In a specific embodiment of the present invention, the device further includes a true chamber ' for receiving the substrate table or support structure and the balance weight. Due to its small stroke, the balance weight of the present invention is particularly suitable for such applications. In a specific embodiment of the present invention, an air box is applied between the balance weight and a wall of the vacuum chamber. This is possible and beneficial due to the small travel of the weight, as any cables and ducts that provide utility to the weight (for example, air for air bearings or cables for position sensors) Wiring through the bellows and therefore does not need to be vacuum dependent. In a specific embodiment of the invention, the bellows forms at least a part of the elastic joint structure. Depending on the stiffness, ‘Fengfengbai’ can partially or completely replace the function of the elastic coupling structure between the balance weight and the base. In a specific embodiment of the present invention, the balance weight actuator or the spring shock absorber system is connected to the balance weight through the bellows. According to another aspect of the present invention, a method for manufacturing a component is provided, whose steps include: 85842 -15-1230844 for a substrate, at least a part of which is covered by a radiation-sensitive material layer on a substrate table on a base; Use a radiation system to provide a radiation projection beam; _ use a patterned member supported by a support structure to give the projection beam a patterned cross-section; I project the patterned radiation beam onto a target portion of a radiation-sensitive material layer_ borrow A reaction force is generated between the substrate table or the support structure and a balance block, so that the substrate table or the support structure is moved relative to the base, and is characterized in that the reaction force is caused by an elastic coupling structure. A part is transmitted to the base, and the elastic coupling structure couples the balance weight to the base at a suspension characteristic frequency between 0.3 and 10 Hz. Although specific references are provided herein for making ICs using the device of the present invention, it must be understood that the device has many other applications. For example, it can be used to manufacture integrated optical systems, magnetic domain memory guidance and detection patterns, liquid crystal display panels, and thin-film magnetic heads. Professionals will understand that in such alternative applications' any of the terms' main mask ',' wafer 'or' die 'used herein must be considered separately by the more general term' mask ' , "Substrate" and "Target section". The terms "radiation" and "beam" used in this document can be used to encompass all types of electromagnetic radiation, including ultraviolet radiation (such as those with a wavelength of 365, 248, 193, 157, or 126 nm) and EUV (extreme ultraviolet radiation, (Such as those with a wavelength range of 5 to 20 nm) 'and particle beams such as ion beams or electron beams. 85842 -16-1230844 [Embodiment] FIG. 1 is a schematic diagram of related parts of a lithographic projection device. The equipment: the dart beam system, "First Ex, il," is used to provide a radiation projection beam pB (such as z-ray, UV EUV radiation, electron beam, etc.), in this particular case, it also includes _ radiation source LA; one object and one object stage (mask stage) MT, which has a mask holder for supporting the mask MA (for example, the main mask), and the first positioning member? 1 ^ connected to accurately position the mask relative to the item PL; a second object table (substrate table) WT, with a substrate support w (eg, a resist-coated silicon wafer)-substrate holder And is connected to the second substrate stage positioning member PW to accurately position the substrate relative to the project;-a projection system ("lens") pL (such as a mirror system) for mapping the irradiated part of the mask MA to the substrate on the target portion of w (eg, containing one or more grains). As described herein, the device is a reverse dance type (ie, has a reflective mask). However, in general, it can also be a transmissive type (for example, having a transmissive mask). Alternatively, the device may use another patterned member, such as a programmable mirror array of the type described above. / The radiation source LA (for example, a laser generating discharge plasma source) generates a radiation beam. This light beam is directed into an irradiation system (illuminator) IL directly or after passing through a regulating member such as the beam expansion two '. The illuminator can include an adjusting member AM ′ for setting the outer radial range and / or the inner radial range of the intensity distribution in the light beam (-generally called • outer and ①inner, respectively). In addition, it generally contains many 85842 -17-1230844 other components, such as an integrator IN and a condenser CO. In this manner, the light beam PB incident on the mask MA has a desired uniformity and an intensity distribution in its cross section. It should be noted in FIG. 1 that the radiation source LA can be located in the housing of the lithographic projection device (usually when the radiation source LA is a mercury lamp, for example), but it can also be far away from the lithographic projection device. The radiation beam generated by it is directed into the device (for example by means of a suitable guide mirror); when the radiation source LA is an excimer laser, this is usually the latter situation. The scope of the invention and the patent application covers both cases. The light beam PB subsequently intercepts the mask MA, which is clamped on it. After passing through the mask µα, the light beam PB passes through the lens PL, which focuses the child beam PB on a target portion c of the substrate w. With the second positioning member (and the interference measurement member IF), the substrate stage boundary 1 can be accurately moved, for example, to position different target portions C in the path of the light beam PB. Similarly, the first positioning member can be used to accurately position the mask ΜA with respect to the path of the light beam PB, for example, after the mask μA is taken out from the mask library mechanically g, or during scanning. Generally speaking, the movement of these object tables MT and WT will be realized with the assistance of a long-line private module (rough positioning) and a short-stroke module (precise positioning). Explained in detail. It should be noted that, in general, the long-travel private module makes the long-distance movement of the substrate stage substantially within a plane, and the long-stroke module of the mask stage makes the long-stroke movement real and people in one direction. However, in the case of a wafer stepper (relatively 10,000; step scanning device), the mask stage may only be connected to a short-stroke actuator to initiate a short-stroke movement of six degrees of freedom, or fixed . 85842 -18-1230844 The above device can be used in two different modes: 1. In the step mode, the mask SMT basically stays still, and an entire mask image is processed at one time (ie a single "flash" ) Projected onto the one-core nuclear point c. Then the substrate table is shifted to the sense and / or y direction, so different targets Shao C can be irradiated by the beam pb; 2. In the scanning mode, substantially the same situation applies, but the specific target portion c is not a single "Quick flash" exposure. Instead, the mask stage Mτ moves in a specific direction (so-called "scanning direction", such as the y direction) at a speed v, so that the projection beam PB scans a mask image; meanwhile, the substrate stage WT is in the same direction Or vice versa at a speed of V = Mv, where μ is the magnification factor of the lens PL (typically 'M-1 / 4 or 1/5). In this way, a relatively large target portion c can be exposed without sacrificing resolution. The present invention will be described in detail with reference to the substrate table WT. However, the present invention is equally applicable to the mask table MT. As can be seen from Figure 1, a typical lithographic apparatus includes a base BF on which various components are supported. For example, FIG. 2 illustrates a schematic diagram of the components installed on the base. This figure shows the base BF which is preferably firmly connected to the ground 10. The projection system PL is not affected by the vibration of the base BF because it is mounted on a measuring frame 50. The measuring frame 50 is connected to the active suspension system 55 by a soft suspension system 55 of an active vibmtiQn isolation system (AVIS). On the base BF. The wafer table is driven by an actuator (20), and the reaction force is applied to the balance block (BM). An elastic coupling structure 150 is connected between the balance weight and the base. The stiffness of the elastic coupling structure 150 should be selected such that the 85842 -19-1230844 balance weight is mounted on the base BF with a suspension characteristic frequency located in the translation (horizontal) plane as the J 卞 plane. The suspension The characteristic frequency is Λ, and the hand < target range is 0.3 to 10 Hz, preferably 1 to 6 Hz. The frequency of a proper prefecture is about 3 Hz. The characteristic frequency fG of the suspension can be calculated according to the equation /: / 一: \ JEnas ① where kspring is the stiffness of the spring of the elastic transition structure 15 °, and is the mass of the balance block BM. If the suspension characteristic frequency of the balance weight is set at. Then the Hertz range Θ, can be a large low-frequency force that allows the base to be knocked down from the balance block to the base in two directions of the translation horizontal plane (at a frequency of less than 3 Hertz, the force reaches about 5_Newton) . In this example, a shock absorber 17 and a balance weight actuator are placed in parallel with the elastic lightweight structure 150. If necessary, the balancer actuator can be mounted on the wind box 120 with a 15G mi structure. According to this method, the elastic Hanhe structure, the shock absorber, and the balance weight actuator are detached from the chamber in which the substrate table operation and the balance weight are positioned. The use of bellows can impose less severe conditions on elastic coupling structures, shock absorbers and balance weight actuators in terms of pollution or degassing characteristics. The weight actuator is used to correct the position of the weight because the weight has a tendency to shift from the correct position. This displacement can be regarded as a hysteresis, which is caused by, for example, the friction between the base BF and the balance weight 3 river. The correction is applied as a closed loop control by a controller that controls the balance weight. The actuator 100 applies a force periodically (for example, every millisecond) (if necessary) to substantially balance the weight BM to prevent the weight from shifting due to repeated movement of the substrate table. 85842 -20- 1230844 The actuator 100 can also be used to suppress the movement of the weight BM to avoid the winding of the weight BM, that is, resonance. Alternatively, this function may be implemented by a separate mechanical passive shock absorber 170. Regardless of the type of shock absorption used, the relevant shock absorption coefficient b should preferably be between 0.5 and ι · 〇 ', and most preferably between 0 and 0. If the balance weight actuator 100 is used, it can be used as an active damper, and the damping coefficient b is changed as a function of frequency. For example, a damping coefficient of b = 0.7 can be used to reach a critical frequency (for example, in the range of 0.3 to 20 Hz), and then the damping coefficient decreases, so that at an infinite frequency, the damping The coefficient is zero. According to this method, the force system transferred from the balance weight to the base at high frequencies is less than the case where the damping coefficient is constant. Since the moving frequency of the base plate WT is close to the suspension characteristic frequency of the balance weight bm, the vibration reduction also reduces the amplitude of the force transfer from the balance weight to the base. The balance weight actuator 100 can also be used to smooth the cross section of the force transmitted to the base at a low frequency by a filtered feedforward program. This system can be accomplished by passing the expected reaction force of the weight BM on the base block through a low-pass filter and applying a force to the weight BM through the weight actuator 100, with the purpose of making a sharp change in the reaction force Becomes smooth. Under no circumstances will high-frequency interference be transmitted to the base. Figure 3 shows an alternative arrangement of various components supported by a base BF in a vacuum application. In this example, the substrate table WT is positioned on a substrate table support frame SF (which is firmly connected to the base) by the connecting member 12. The wafer stage is driven by an actuator (20), and the reaction force is applied to the balance weight (_). The elastic coupling structure 150 and the shock absorber 170, which are parallel to the balance weight actuator ⑽, are connected between the balance weight and the base plate support frame. In 85842 -21-1230844, this tool is also the same. In this case, the projection system PL, the balance weight BM, and the substrate table WT are packaged in a true 2-chamber VC, and the vacuum chamber is firmly connected to the base brain. The substrate opening WT and the balance weight BM should be installed so that the translational movement in a horizontal plane parallel to the surface of the substrate stage support frame SF is substantially friction-free. This goal can be achieved by, for example, suspending the substrate table WT from the weight and providing a line bearing for the weight, or both the substrate table and
該平衡塊提供空氣軸承，使其重量可以為基板台支撐架SF 所支彳牙。邊平衡塊也可以懸置於彈性機械彈簧或氣動彈簧 之上。 在啟動定位致動器20來產生一反作用力時，基板台WT與 平衡塊BM會朝相反方向平移。 該平衡塊BM係彈性耦合至該基板台支撐架兕，並因而以 一彈性彈簧耦合結構150與該底座即連接。選擇彈性耦合結 構150的勁度時，應使得該平衡塊以該平移（水平）平面中的 一 0.3與10赫茲（最好為i至6赫茲）之間的懸掛特徵頻率，將該 平衡塊安裝於該晶圓臺支撐架邱上。適當的懸掛特徵頻= 為3約赫茲。 圖4顯示典型出現於該掃描方法中的加速力與減速力。加 速力與減速力係兼在時域與頻域内顯示。在此實例中，最 大加速力為約1500 [N]。功率譜或每頻帶之能量亦顯示出來取 在典型情況中，該加速度分佈功率譜顯示了低於2〇 [Hz]之頻 率處的較大力。在此率之上，殘留的能量非常少。 當在0·3至10赫茲範圍内為該平衡塊施加一懸掛特徵頻率 時，由於該平衡塊在此處係以傳統的自由塊方式起作用， 85842 -22- 1230844 故該基板台WT的短行程平移移動(其係在約腿㈣、茲及以 上的頻率處出現）幾乎不轉移至該底座上。然而，對於該基 板台WT的長行程平移移動(其係在低於約15赫兹的一較低二 率處出現）來說，至少有—部分反作用力係轉移到該基板台 支撐架SF’從而轉移該底座BFm，當部分反作用力⑼％ 與腦之W)係藉合結構15_加至職板台支撐架 SF上時，用於低頻率移動的該平衡塊所要求的位移會減少。 頃發現’以水平平料向倒人白勺此種#交大但頻率較低的力 可以施加於該底座BF(在低於3赫茲的頻率處，典型約為1〇⑻ 至5000牛頓）’而不會對裝置的性能產生有害的影響。 圖5顯示用於本發明之數項具體實施例的平衡塊力向底座 轉移的預示曲線圖。此圖顯示了平衡塊力與底座力之比（單 位：dB)同頻率[Hz]的對照。作為參考，一自由安裝的平衡 塊（即一牛頓平衡塊）的特性係作為曲線圖G〇顯示。依據牛 頓的「作用力=反作用力」原理操作的—完美平衡塊，會吸 收所有能量，並因此不能向底座傳輸力。一不甚完美的的 牛頓平衡塊會以較低頻率部分傳輸非常少量的力。一牛頓 平衡塊的不利之處在於：該移動或偏移係等於平衡塊與基 板台的質量比。 务一彈性轉合結構係連接於該平衡塊與該底座之間，則 該平衡塊的偏移可以大大減少。然而，其結果導致較低頻 率力係直接傳輸（至該底座），且在該共振頻率中，該底座力 可以比忒平衡塊力咼出許多（見曲線圖G1所示）。在該共振 頻率之上，該未減震平衡塊再次減少倒入該底座的力，並 85842 -23 - 1230844 形成具有一 -40 [dB/dec]滾降（r〇ll-0ff)的一機械濾波器。在該共 振頻率處的放大係藉由平行於該平衡塊與該底座之間的該 彈性摘合結構施加一被動減震器來減少（如曲線圖G3所 示）°然而，此減震後的平衡塊的機械濾波器隨後僅具有一 -20 [dB/dec]的滾降。 當該減震元件係藉由與一彈簧串聯的一減震器來形成 時’儘管該過濾係在一高頻率處啟動，此彈性耦合結構與 彈簧減震器系統的組合系統（亦稱為KDK系統）仍會再次具有 一 -40 [dB/dec]的滾降。如曲線圖G3所示，此kdk系統平衡塊 的性能係優於曲線圖G2中顯示的該減震後的平衡塊。 在另一項具體實施例中，應用了一控制迴路，其係藉由 該平衡塊與該底座之間一致動器及用來量測該平衡塊相對 於該底座之位置的一位置感應器形成。可以按一方法調節 薇控制器，使其不但可以獲得該共振頻率的減震，而且可 以維持該急劇升降的-40 [dB]滾降（見曲線圖G4)。 圖ό顯示該平衡塊移動向該反作用力轉移的預示曲線圖。 在低頻時，作為該輸入力函數的該平衡塊移動係與該彈性 耦合結構勁度的倒數成正比。因此，平衡塊與底座之間一 le5 [N/m]的勁度會造成每輸入的力，會產生le_5 [m]的位移（因 此該轉移為le-5 [m/N]或-100 dB)。對於1500 [N]的力，該位移為 約15 mm。若勁度增加，則移動會減少相同的倍數，但用於 輸出力的頻帶亦會增加（見圖6及等式丨）。因此，一軟彈性輕 合結構伴隨軟力發生（強平衡塊過滤），但也會出現較大的偏 移。一硬彈性耦合結構具有硬力（弱過濾），但偏移較小。某 85842 -24- 1230844 種程度上’在平衡塊偏移與力過濾性能之間可以找到一適 當折衷。使用具有非線性特徵的—彈性耦合結構可以用來 碉=此折衷。可採用線性及非線性彈簧型元件來實現之。 此等元件可以在平_與底座之間_，其排财式使得， 當該平衡塊從其中性位置處移開，其勁度會不斷增加。 在該共振頻率附近，若未呈現減震（圖6中顯示的放大約為ι〇〇 X !)，則該位移會放大。為避免此情況，應將一減震元件與 孩彈性耦合結構結合。圖6之曲線圖⑴顯示該未減震系統的 特被，G2顯不該已減震系統的特徵，⑺顯示該系統的 特徵，且G4顯示與該平衡塊致動器結合的彈性耦合結構之 特徵。在該已減震系統（G2、G3、G4)中，在共振頻率處的 遠未減震系統中出現的放大係被削弱◊就高頻而言，所有 系統均具有一 _4〇 dB/dec的滚降’因此’具有極高頻之力僅能 產生較小的平衡塊位移。 圖7為本發明之一項具體實施例的示意圖，其中，該KDK 系統係應用於該平衡塊與該底座之間。該KJ3K系統為一被 動系統’其包括與一彈簧減震器系統18〇平行的一彈性耦合 結構150 ’該彈簧減震器系統18〇包括一具有彈簧特性的元 件’其係與一具有減震器特性的元件牟聯。此KDK系統可 結合封裝該KDK系統的一風箱12〇來應用，以便使用非該KDK 系統之真空依賴型的材料或組件。該風箱也可以部分或全 部取代該彈性耦合結構15〇之功能。圖中顯示的該KDK系統 也可在圖3中顯示的一項具體實施例的内部應用，作為結合 有一平衡塊致動器的彈性耦合結構之替代方案。 85842 -25- 1230844 在一真空應用中，該平衡塊BM係藉由金屬風箱120連接至 該真空室VC之壁，金屬風箱120可以藉由焊接一曲板或將一 寬管與薄壁扣合而製作。該風箱允許彈性耦合結構150及致 動器100或KDK系統安放在真空室VC之外，使其設計要求不 甚嚴格，以便無須依賴真空（例如符合除氣標準）。而且，可 以藉由管道或電纜，穿過風箱120將效用提供至平衡塊BM。 由於在基板台WT定位過程中，平衡塊BM經歷了較小行程， 故有可能使用風箱120。該風箱至少可以形成部分該平衡塊 BM與該底座的彈性耦合結構。 圖8顯示該平衡塊BM與該底座之連接的一選擇性佈局， 在此項具體實施例中，該底座係該真空室牆壁VC之部分。 彈性耦合結構150與平衡塊致動器100係安放在一二級真空室 210内的基板台真空室之中，該二級真空室210可以方便地處 於比該基板台真空室VC更高的壓力之下。一連接構件200將 彈性耦合結構150與平衡塊致動器100連接至該基板台真空室 壁VC上。該二級真空室200與該漣接室之間要求密封或封 閉。在圖9說明的選擇中，連接構件200將平衡塊BM連接至 彈性耦合結構150及平衡塊致動器100，平衡塊致動器100係 直接連接至底座BF。在此項具體實施例中，該基板台真空 室VC係與該底座分開，使得定位於真空之外的該平衡塊致 動器BM無須為真空依賴型。該基板台真空室VC與該連接構 件200之間要求進行密封。 圖10為在該平衡塊BM與該底座BF之間連接的一 KDK系統 的示意圖。該平衡塊係藉由軸承系統215來支撐。該KDK系 85842 -26- 1230844 統包括一彈性耦合結構150與一彈簧減震器系統，該彈簧減 震器系統包括彈簧240與一渦流減震器，該渦流減震器係由 磁性板220與定位於二磁性板之間的一導電板23〇組成。 該平衡塊BM可以具有1至6度的自由度，但最好為3度自 由度（在水平平面之中）或6度自由度（兼在水平平面與垂直平 面之中）。本發明中描述的位於平衡塊與支撐架之間的該搞 合結構在該基板台或支撐結構有移動的所有自由度中均可 應用。位於平衡塊與支撐架之間的彈性耦合結構對於該等 不同的自由度可以具有不同的特性。該彈性耦合結構可以 進一步與一平衡塊致動器及/或對於該等不同自由度而具有 不同特性的一彈簧減震器系統結合。舉例而言，圖η顯示 一可能排列的頂視圖，其中，該等彈性耦合結構15〇係一平 衡塊ΒΜ與一底座BF之間的彈簧。應該清楚，已描述的該彈 性耦合結構可以與該KDK系統結合，或與一減震器及一平 衡塊致動器結合。還應該注意，在此排列中，儘管只有乂及 Υ方向上的彈簧適用，但該平衡·塊係在3度的自由度（χ、Υ 及Rz)中轉合。用來定義不同自由度中彈性輕合結構的此方 法在3度以上的自由度中也可以適用。 雖然本發明的特定具體實施例已如上加以說明，但應明 瞭本發明可以上述以外的其他方法完成。本發明並不受本 說明所限制。 【圖式簡單說明】 現在將參考附圖並藉由實例說明本發明的具體實施例， 其中： 85842 -27- 1230844 圖1顯示一微影投影裝置的相關零件。 之一微影投影裝 適合於真空應用 圖2顯示依據本發明的一項具體實施例 置。 圖3顯示依據本發明的一項具體實施例 的一微影投影裝置。 圖4顯示掃描方法在時域及頻域中的一典型力圖案。 圖5顯示在用於本發明之不同具體實施例的頻域中，該反 作用力向該底座轉移的情況。 圖6顯示在用於本發明之不同具體實施例的頻域中，該平 衡塊位移至該底座力的轉移功能。 圖7顯示依據本發明之一項具體實施例來連接該底座與該 平衡塊的KDK系統。 圖8顯示依據本發明之一項具體實施例，用於該平衡塊與 該底座連接的一替代排列。 圖9顯示依據本發明之一項具體實施例，用於該平衡塊與 該底座連接的另一替代排列。 .圖10為包括一渦流減震器的一 KDK系統的示意圖。 圖11為在水平平面之3度自由度中耦合的一平衡塊的示意 圖0 在圖中’對應的參考符號表示對應的零件。 【圖式代表符號說明】 am 調節構件 BF 底座 bm 平衡塊 85842 -28- 1230844 c 目標部分 CO 聚光器 Ex 光束擴張器 G0-G4 曲線圖 IF 干涉量測裝置 IL 照射系統 IN 整合器 LA 輻射源 MA 遮罩 MT 遮罩台 PB 投影光束 PL 項目 PM 第一定位構件 PW 第二基板台定位構件 SF 基板台支撐架 VC 真空室 . W 基板 10 地面 12 連接構件 20 致動器 50 度量架 55 軟懸掛系統 100 平衡塊致動器 120 風箱 85842 -29- 1230844 150 彈性耦合結構 170 減震器 180 彈簧減震器系統 200 連接構件 210 二級真空室 215 軸承系統 220 磁性板 230 導電板 240 彈簧 85842 - 30The balance weight provides air bearings so that its weight can be supported by the cavities supported by the substrate stage support frame SF. The side balance weight can also be suspended on the elastic mechanical spring or pneumatic spring. When the positioning actuator 20 is activated to generate a reaction force, the substrate table WT and the weight BM are translated in opposite directions. The balance weight BM is elastically coupled to the substrate table support frame 兕, and is thus connected to the base with an elastic spring coupling structure 150. When selecting the stiffness of the elastic coupling structure 150, the balance weight should be installed at a suspension characteristic frequency between 0.3 and 10 Hz (preferably i to 6 Hz) in the translational (horizontal) plane. On the wafer table support frame Qiu. Proper suspension characteristic frequency = about 3 Hz. Figure 4 shows the acceleration and deceleration forces typically found in this scanning method. The acceleration and deceleration forces are displayed in both the time and frequency domains. In this example, the maximum acceleration is about 1500 [N]. The power spectrum or energy per band is also shown. In a typical case, the acceleration distribution power spectrum shows a large force at frequencies below 20 [Hz]. Above this rate, very little energy remains. When a suspension characteristic frequency is applied to the balance weight in the range of 0.3 to 10 Hz, since the balance weight functions here in a traditional free-block manner, 85842 -22-1230844 therefore the short length of the base plate WT Stroke translational movements (which occur at frequencies of approximately ㈣, 兹, and above) are hardly transferred to the base. However, for the long-stroke translational movement of the substrate table WT (which occurs at a lower second rate below about 15 Hz), at least part of the reaction force is transferred to the substrate table support frame SF 'so that When the base BFm is transferred, when a part of the reaction force ⑼% and the brain W) is added to the work table support frame SF, the required displacement of the balance weight for low-frequency movement will be reduced. It was found that 'this kind of # cross-linked but relatively low-frequency force can be applied to the base BF (at a frequency below 3 Hz, typically about 10⑻ to 5000 Newtons) with a horizontal flat material' and It will not adversely affect the performance of the device. Fig. 5 shows a predictive graph of the transfer of the balance weight force to the base for several embodiments of the present invention. This figure shows the comparison of the ratio of the balance force to the base force (unit: dB) and the frequency [Hz]. For reference, the characteristics of a freely installed balance weight (ie, a Newton balance weight) are shown as graph G0. Operated according to Newton's "force = reaction force" principle-a perfect balance block will absorb all energy and therefore cannot transmit force to the base. An imperfect Newton's balance block transmits a very small amount of force at a lower frequency. The disadvantage of a Newton weight is that the movement or offset is equal to the mass ratio of the weight to the base plate. If a flexible turning structure is connected between the balance weight and the base, the offset of the balance weight can be greatly reduced. However, the result is that the lower-frequency force is transmitted directly (to the base), and at this resonance frequency, the base force can be much larger than the 忒 balance weight (see graph G1). Above the resonance frequency, the undamped balance weight again reduces the force falling into the base, and 85842 -23-1230844 forms a mechanism with a -40 [dB / dec] roll-off (r0ll-0ff) filter. The amplification at the resonance frequency is reduced (as shown in graph G3) by applying a passive shock absorber parallel to the elastic coupling structure between the balance weight and the base. However, the The mechanical filter of the balance block then has a roll-off of only -20 [dB / dec]. When the shock absorbing element is formed by a shock absorber connected in series with a spring, 'Although the filtering system is activated at a high frequency, the combined system of the elastic coupling structure and the spring shock absorber system (also known as KDK System) will still have a roll-off of -40 [dB / dec]. As shown in graph G3, the performance of the kdk system balance weight is better than the damped balance weight shown in graph G2. In another specific embodiment, a control loop is applied, which is formed by an actuator between the balance weight and the base and a position sensor for measuring the position of the balance weight relative to the base. . The Wei controller can be adjusted in a way that it can not only obtain the vibration damping of the resonance frequency, but also maintain the -40 [dB] roll-off of the sharp rise and fall (see graph G4). Figure ix shows the predictive curve of the movement of the counterweight to the reaction force. At low frequencies, the balance moving system as a function of the input force is proportional to the inverse of the stiffness of the elastic coupling structure. Therefore, a stiffness of le5 [N / m] between the weight and the base will cause a displacement of le_5 [m] for each input force (so the shift is le-5 [m / N] or -100 dB ). For a force of 1500 [N], this displacement is approximately 15 mm. If the stiffness is increased, the movement will decrease by the same multiple, but the frequency band used for output force will also increase (see Figure 6 and Equation 丨). Therefore, a soft-elastic lightweight structure is accompanied by a soft force (strong balance block filtering), but a large offset will also occur. A hard-elastic coupling structure has a hard force (weak filtering) but a small offset. At some 85842-24-2430844 degrees, a proper compromise can be found between balance weight shift and force filtering performance. The use of a non-linearly-elastic coupling structure can be used to 碉 = this compromise. This can be achieved with linear and non-linear spring-type elements. These elements can be between the flat and the base, and their wealth-saving style allows the stiffness of the weight to increase when the weight is moved away from its neutral position. In the vicinity of this resonance frequency, if vibration reduction is not present (the magnification shown in FIG. 6 is about 〇 ×!), The displacement will be magnified. To avoid this, a damping element should be combined with the elastic coupling structure. The graph in Fig. 6 ⑴ shows the special features of the undamped system, G2 shows the characteristics of the damped system, ⑺ shows the characteristics of the system, and G4 shows the elastic coupling structure combined with the balance weight actuator. feature. In this damped system (G2, G3, G4), the amplification system appearing in the far less damped system at the resonance frequency is weakened. As far as the high frequency is concerned, all systems have a _4dB / dec. The roll-off 'so' with extremely high frequency forces can only produce small balance weight displacements. FIG. 7 is a schematic diagram of a specific embodiment of the present invention, wherein the KDK system is applied between the balance weight and the base. The KJ3K system is a passive system. It includes an elastic coupling structure 150 parallel to a spring shock absorber system 180. The spring shock absorber system 18 includes a spring-like element. Of device characteristics. The KDK system can be applied in conjunction with a bellows 120 that encapsulates the KDK system, so that materials or components that are not vacuum-dependent on the KDK system can be used. The bellows can also partially or completely replace the function of the elastic coupling structure 15. The KDK system shown in the figure can also be applied internally of a specific embodiment shown in FIG. 3 as an alternative to an elastic coupling structure incorporating a balance weight actuator. 85842 -25- 1230844 In a vacuum application, the balance block BM is connected to the wall of the vacuum chamber VC by a metal bellows 120. The metal bellows 120 can be welded with a curved plate or fastened with a wide tube and thin wall. While making. The bellows allows the elastic coupling structure 150 and the actuator 100 or KDK system to be placed outside the vacuum chamber VC, making its design requirements less stringent so as not to rely on vacuum (for example, to meet degassing standards). Moreover, the utility can be provided to the balance weight BM through the bellows 120 through pipes or cables. Since the weight BM has undergone a small stroke during the positioning of the substrate table WT, it is possible to use the bellows 120. The bellows can form at least part of the elastic coupling structure of the balance block BM and the base. FIG. 8 shows a selective layout of the connection between the balance block BM and the base. In this specific embodiment, the base is part of the wall VC of the vacuum chamber. The elastic coupling structure 150 and the balance weight actuator 100 are placed in a substrate stage vacuum chamber in a first-stage vacuum chamber 210, and the second stage vacuum chamber 210 can be conveniently at a higher pressure than the substrate stage vacuum chamber VC. under. A connecting member 200 connects the elastic coupling structure 150 and the weight actuator 100 to the substrate table vacuum chamber wall VC. The secondary vacuum chamber 200 and the ripple chamber are required to be sealed or closed. In the option illustrated in Fig. 9, the connecting member 200 connects the balance weight BM to the elastic coupling structure 150 and the balance weight actuator 100, and the balance weight actuator 100 is directly connected to the base BF. In this specific embodiment, the substrate table vacuum chamber VC system is separated from the base, so that the balance weight actuator BM positioned outside the vacuum need not be a vacuum-dependent type. The substrate stage vacuum chamber VC and the connection member 200 are required to be sealed. Fig. 10 is a schematic diagram of a KDK system connected between the balance weight BM and the base BF. The balance weight is supported by a bearing system 215. The KDK system 85842 -26-1230844 system includes an elastic coupling structure 150 and a spring shock absorber system. The spring shock absorber system includes a spring 240 and an eddy current shock absorber. The eddy current shock absorber is composed of a magnetic plate 220 and A conductive plate 23 is positioned between the two magnetic plates. The balance weight BM may have a degree of freedom of 1 to 6 degrees, but is preferably 3 degrees of freedom (in a horizontal plane) or 6 degrees of freedom (in a horizontal plane and a vertical plane). The engaging structure described between the balance weight and the support frame described in the present invention can be applied in all degrees of freedom in which the substrate table or the support structure has movement. The elastic coupling structure located between the balance weight and the support frame may have different characteristics for these different degrees of freedom. The elastic coupling structure may be further combined with a balance weight actuator and / or a spring shock absorber system having different characteristics for the different degrees of freedom. For example, Fig. N shows a top view of a possible arrangement, in which the elastic coupling structures 15 are springs between a balance block BM and a base BF. It should be clear that the elastic coupling structure already described may be combined with the KDK system, or with a shock absorber and a balance weight actuator. It should also be noted that in this arrangement, although only springs in the 乂 and Υ directions are applicable, the balance block is turned in 3 degrees of freedom (χ, Υ, and Rz). This method used to define the elastic lightweight structure in different degrees of freedom can also be applied in degrees of freedom above 3 degrees. Although the specific embodiments of the present invention have been described above, it should be understood that the present invention can be carried out by methods other than the above. The invention is not limited by this description. [Brief Description of the Drawings] A specific embodiment of the present invention will now be described with reference to the drawings and examples, wherein: 85842 -27-1230844 FIG. 1 shows relevant parts of a lithographic projection device. One of the lithographic projection devices is suitable for vacuum applications. Fig. 2 shows a specific embodiment according to the present invention. Fig. 3 shows a lithographic projection apparatus according to a specific embodiment of the present invention. FIG. 4 shows a typical force pattern of the scanning method in the time domain and the frequency domain. Fig. 5 shows a situation where the reaction force is transferred to the base in the frequency domain used in different embodiments of the present invention. Fig. 6 shows the force transfer function of the balance block moving to the base force in the frequency domain used in different embodiments of the present invention. FIG. 7 shows a KDK system for connecting the base and the balance weight according to a specific embodiment of the present invention. Fig. 8 shows an alternative arrangement for connecting the balance weight to the base according to a specific embodiment of the invention. Figure 9 shows another alternative arrangement for connecting the balance weight to the base according to a specific embodiment of the invention. FIG. 10 is a schematic diagram of a KDK system including an eddy current shock absorber. Fig. 11 is a schematic view of a balance weight coupled in 3 degrees of freedom in a horizontal plane. Fig. 0 In the figure, the corresponding reference symbols indicate corresponding parts. [Illustration of representative symbols of diagrams] am Adjustment member BF base bm Balance weight 85842 -28- 1230844 c Target part CO Concentrator Ex Beam expander G0-G4 Graph IF Interference measurement device IL Irradiation system IN Integrator LA Radiation source MA mask MT mask table PB projected beam PL item PM first positioning member PW second substrate table positioning member SF substrate table support frame VC vacuum chamber. W substrate 10 floor 12 connection member 20 actuator 50 measuring frame 55 soft suspension System 100 balance weight actuator 120 bellows 85842 -29- 1230844 150 elastic coupling structure 170 shock absorber 180 spring shock absorber system 200 connecting member 210 secondary vacuum chamber 215 bearing system 220 magnetic plate 230 conductive plate 240 spring 85842- 30